Field
One or more embodiments relate to a lithium battery.
Description of the Related Technology
Lithium secondary batteries have high voltage and high energy density and thus, are used in various applications. For example, electric vehicles (HEV or PHEV) require lithium secondary batteries with excellent discharge capacity and lifespan characteristics because they operate at high temperature, to be charged or discharged with a great amount of electricity, and to be used for a long period of time.
Carbonaceous materials are porous and thus, during charging and discharging, they undergo less volumetric change. However, due to the porous structure of carbonaceous materials, a battery using the carbonaceous material has a small battery capacity. For example, a theoretical capacity of graphite having high crystallinity is, when it has a composition of LiC6, 372 mAh/g.
As a negative active material having higher electric capacity than the carbonaceous materials, a lithium-alloyable metal may be used. For example, the lithium-alloyable metal may be Si, Sn, Al, or the like. However, the lithium-alloyable metal may be easily deteriorated and thus its lifespan characteristics may be poor. For example, in the case of Sn, during repeated charging and discharging, Sn particles may be repeatedly aggregated and crushed and thus, Sn particles may be electrically insulated.
Accordingly, there is a need to develop a lithium battery with improved discharge capacity and lifespan characteristics.